#include <bits/stdc++.h>

 using namespace std;

 const int maxn = 1e5 + ;

 __int64 cnt,k;

 int a[maxn],c[maxn];

 void merge(int* a,int first,int mid,int last,int* c) {

     int i = first,j=mid+;

     int m = mid,n=last;

     int k = ;

     while(i<=m||j<=n) {

         if(j>n||(i<=m&&a[i]<=a[j])) {

             c[k++] = a[i++];

         }

         else {

             c[k++] = a[j++];

             cnt += (m-i+);

         }

     }

     for(i=;i<k;i++)

         a[first+i] = c[i];

 }

 void mergeSort(int* a,int first,int last,int* c) {

     if(first<last) {

         int mid = (first+last)/;

         mergeSort(a,first,mid,c);

         mergeSort(a,mid+,last,c);

         merge(a,first,mid,last,c);

     }

 }

 int main()

 {

     int n;

     while(~scanf("%d%I64d",&n,&k)) {

         for(int i=;i<n;i++)

             scanf("%d",&a[i]);

         memset(c,,sizeof(c));

         cnt = ;

         mergeSort(a,,n-,c);

         printf("%lld\n",max(cnt-k,0LL));

     }

     return ;

 }